Upright free-standing shelf unit



FIG. 1 is an isometric view of the upright free-standing shelf unit embodying our design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a back elevational view thereof;

FIG. 4 is a right-side elevational view thereof, the left-side elevational view being a mirror image thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for an upright free-standing shelf unit, as shown and described. 